Method and device for jointing of cores

ABSTRACT

End-to-end joining of sleeves. A first glue strand is applied to the end joint surface of one of the sleeves, the first glue strand having properties that cause an immediate fixing of the end joint surfaces of the sleeves. A second glue strand is applied to the end joint surface of one of the sleeves, the second glue strand having properties that causing wetting of the sleeve material in the joint surface and its immediate vicinity. The end joint surface of a first one of the sleeves is positioned against the end joint surface of a second one of the sleeves so that the first glue strand causes an immediate fixing of the end joint surfaces, and the second glue strand is allowed to set. The apparatus includes alignment devices for positioning the sleeves adjacent glue nozzles and for positioning the sleeves in end-to-end contact.

FIELD OF THE INVENTION

The present invention relates to a method of joining cores, e.g.,paperboard sleeves which in the paper industry are used to support rollsof paper. Further, the present invention relates to an apparatus forcarrying the method into effect.

BACKGROUND OF THE INVENTION

Within, among others, the paper industry, there has become a steadilyincreasing need to be able to join sleeves of, above all, paperboard inorder to be able to reuse sleeves which would otherwise be scrapped.However, extremely strict demands are placed on the quality of thejoined sleeves. This relates in particular to the joint itself whichmust be strong (show considerable mechanical strength in all axes) andwhich must keep the sleeve sections aligned with one another and withcorrect roundness. The mechanical strength requirements are particularlylarge since a sleeve breakage can lead to serious accidents with bothpersonal injuries and serious damage to machinery.

The task forming the basis of the present invention is to realise anovel method and a novel apparatus for joining sleeves of the typedisclosed by way of introduction.

Through the present invention, there will be realised a method ofjoining sleeves, whereby the joints display extraordinary mechanicalstrength and great accuracy as regards alignment and roundness. Themethod according to the present invention also permits the realisationof a simple and reliable apparatus for carrying out the method. Anapparatus according to the present invention permits a high degree ofautomation.

BRIEF DESCRIPTION OF THE DRAWING

The present invention will be described in greater detail hereinbelowwith reference to the accompanying drawings.

FIG. 1 shows a schematic view of a future joint between two sleeves,parts having been broken away for purposes of clarity.

FIG. 2 shows on a large scale a view partly in section of a part of thefuture joint in FIG. 1.

FIG. 3 shows a view of a part of an apparatus for realising the joint inFIG. 1 and 2.

FIG. 4 shows a view of the apparatus in FIG. 3 under execution ofanother work phase.

FIG. 5 shows a view of another part of an apparatus for realising thejoint in FIG. 1 and 2.

FIG. 6-12 show cross sections of different types of joints.

FIG. 13 shows a view of a joint.

FIG. 14-30 show simplified cross sections of different types of joints.

DETAILED DESCRIPTION

In the different drawing figures, the same parts have been given thesame reference numeral. In FIG. 1 parts are exemplified of twopaperboard sleeves 1 and 2 which are to be joined together to oneanother. In this case, the sleeve 2 is provided with an inner conicalsurface 3, while the sleeve 1 is provided with an outer conical jointsurface 4. On the conical joint surface 3 there is applied a first gluestrand 5 and a second glue strand 6. The glue strand 5 may consist of amelt glue, while the glue strand 6 consists of a dispersion glue. It isalso possible to cause the glue strand 5 to consist of a dispersionglue, while the glue strand 6 in such case consists of a melt glue.

For achieving a good joint quality, it has proved to be particularlyimportant that the one glue strand consists of a glue of such propertiesthat it gives an immediate fixing after closure of the joint in that thesleeves 1 and 2 are moved towards one another and exercising of asuitable compression pressure. One such glue is a melt glue. If the oneglue strand, e.g. 5, consists of a melt glue, it is suitable that theother glue strand consist of a glue which has such properties that theglue wets the sleeve material and penetrates in between the fibres andsets, for example, by drying. Such properties possess a dispersion glueor PVA glue.

The primary duty of the melt glue strand is to fix the two sleeve parts1 and 2 into a unit, which can be transported and after-processed by,for example, cleaning. The dispersion glue joint serves substantially toimpart, after setting, the mechanical strength which is sought for useof the sleeve formed by the sleeve parts 1 and 2.

The glue strand 5, 6 need not necessarily be continuous but may bediscontinuous. Further, the one glue strand may be discontinuous and theother continuous. In the case when both glue strands are discontinuous,it may be appropriate that the glue sections of the one glue strandcover the spaces between the glue sections in the other glue strand.

FIG. 2 shows, on a large scale, a part of the glue joint of FIG. 1.

In FIGS. 3, 4 and 5, are shown parts of an apparatus for realising ajoint of the type illustrated in greater detail in FIGS. 1 and 2. FIG. 3shows the sleeve section 1 placed on two rollers 7 which are placed sideby side, only the one roller being apparent in the figure. Above therollers 7 and the sleeve 1, there is disposed an additional roller 8which serves to hold the sleeve 1 on the rollers 7 or to urge the sleeve1 against the rollers 7. Possibly, the roller 8 may be utilised forrotation of the sleeve 1 on the rollers 7. It also conceivable toprovide a separate drive means for rotation of the sleeve 1 in theroller package formed by the rollers 7 and 8.

At the end of the sleeve section 1, there is disposed a miller 9 whichis driven by a motor 10 and which is placed at an angle to the sleeve 1for processing the sleeve end edge in the desired angle for realisingthe joint surface 4 which is shown in FIGS. 1 and 2. The miller 9 andthe motor 10 are disposed on a carriage 11 which is displaceable on asliding rail 12 in the longitudinal direction of the sleeve 1. Thecarriage 11 supports a support roller 13 which is positioned on the endof an arm 14 which extends out from the carriage 11. The sliding rail 12is displaceable at right angles to the sleeve 1 on a sliding rail 15 atright angles in relation to the sliding rail 12. The sliding rail 12 andthe carriage 11 may be adjustable with the aid of a gear rack, threadspindle or the like.

FIG. 4 illustrates substantially the same apparatus as in FIG. 3, butwith the parts in position for processing the sleeve section 2 andrealising the joint surface 3, which implies that the inside of thesleeve section 2 is processed with the aid of the miller 9. Thus, thesame apparatus may be employed for processing both the sleeve section 1and the sleeve section 2 for creating, on the one hand, the femalesurface 3 and, on the other hand, the male surface 4.

After the processing of the sleeve sections 1 and 2 described inconnection with FIGS. 3 and 4 for forming the joint surfaces 3 and 4,the sleeve sections 1 and 2 are to be aligned accurately with oneanother and this may be carried into effect with the aid of thealignment devices 16 and 17 shown in FIG. 5. As is apparent from FIG. 5,the alignment devices 16 and 17 are substantially identical and displaya number of guide rails 18 which extend between two support walls 19 and20, the guide rails 18 being outwardly bent at the one end in order tofacilitate insertion of the sleeve sections 1 and 2. After the insertionof the sleeve sections 1 and 2 in the alignment devices 16 and 17, thealignment devices may be displaced to the position illustrated in FIG. 5in which the longitudinal axes of the sleeve sections 1 and 2 arealigned with one another. This alignment of the alignment devices maynaturally take place mechanically on some form of machine bed usingrails or the like. At the joint formed between the sleeve sections 1 and2 there is provided a nozzle M5 for application or coating of the gluestrand 5 and a nozzle M6 for application of the glue strand 6. Thenozzles M5 and M6 can be given a substantially optional positioningwhich is appropriate in the different individual cases. As was mentionedabove, the one nozzle M5 serves for application of melt glue while theother nozzle M5 serves for application of a dispersion glue. The nozzlesM5 and M6 are each connected to their glue container via a suitablevalve (not shown) for regulating the supply of glue to the glue strandson the joint surface or joint surfaces.

After the application of the glue strands, the alignment devices aredisplaced towards one another, or the one sleeve section 1 is displacedinto the other sleeve section 2 which, in such an event, is held fixedagainst axial movement. The compression pressure may be determinedempirically and thereafter all joints can be pressed together withexactly the same compression pressure.

FIGS. 6-13 exemplify a number of joints. FIG. 6 shows a cylindrical maleand female joint. In FIG. 7 is shown a joint with an insert 21. FIG. 8shows a joint with a special outer portion 22. FIG. 9 shows a joint witha specially formed insert 21. FIG. 10 shows a joint with a speciallyformed outer portion 22. In FIG. 11 is shown a similar joint to FIGS. 1and 2. FIG. 12 shows a special joint where the end surfaces of thesleeve sections 1 and 2 are straight or at right angles to thelongitudinal axis of the sleeve sections 1, 2 and there a number ofholes have been drilled axially in each sleeve section for the insertionof pins 23. FIG. 13 shows a further joint with toothed form. Oneadvantage with the sleeve joints in FIGS. 7, 8, 9, 10, 12 and 13 is thatthe ends of the sleeve sections are processed in substantially the sameway.

FIGS. 14-30 exemplify a further additional number of joint forms. FIG.14 shows a conical joint with an outer and an inner planar supportsurface. FIG. 15 shows only a straight joint. FIG. 16 shows an arrowheadjoint with a support surface. FIG. 17 shows a Z joint. FIG. 18 shows ajoint with a bead 24. FIG. 19 shows a joint with a planar portionbetween oblique surfaces 25. FIG. 20 shows a joint with an angledportion 26 which makes an angle with the longitudinal axis of the sleevesections. FIG. 21 shows a joint with rounded-off ends and planar centralportion. FIG. 22 shows an echelon joint. FIG. 23 shows a conical jointwith inner support surface. FIG. 24 shows a tipped joint. FIG. 25 showsa rounded-off joint. FIG. 26 shows a conical joint with outer supportsurface corresponding to the joint in FIG. 23. FIG. 27 shows atoothed/or threaded joint. FIG. 28 shows a plug joint. FIG. 29 shows atongued and grooved joint. FIG. 30 shows a joint with gable topsurfaces.

It is also possible to place the one glue strand 5 on the one jointsurface 3 and the other glue strand 6 on the other joint surface 4. Itis further possible to make many other combinations and distributions ofthe glue strands 5 and 6 on the joint surfaces 3 and 4. In the apparatusillustrated in FIG. 5, the rails 18 may be replaced by or combined withwheels and/or rollers.

Many modifications are naturally possible without departing from theinventive concept as defined in the appended claims.

1. A method of end-to-end joining of two cylindrical sleeves, eachcylindrical sleeve having an outer cylindrical surface and an innercylindrical surface and including an end joint surface on the end ofsuch cylindrical sleeve, said method comprising: applying a strand of afirst glue to at least a part of the width of the end joint surface ofone of the cylindrical sleeves, the first glue having properties thatcause fixing of the end joint surfaces of the sleeves within a firsttime period; and applying a strand of a second glue to at least a partof the width of the end joint surface of one of the cylindrical sleeves,the second glue having properties that causing wetting of the sleevematerial in the joint surface and its immediate vicinity; positioningthe width of the end joint surface of a first one of the cylindricalsleeves against the width of the end joint surface of a second one ofthe cylindrical sleeves so that the first glue strand by itself causesfixing of the end joint surfaces within the first time period; andallowing the second glue strand to set by itself within a second timeperiod, longer than the first time period.
 2. A method according toclaim 1, wherein the first glue comprises a melt glue.
 3. A methodaccording to claim 1, wherein the second glue comprises a dispersionglue.
 4. A method according to claim 1 wherein one of the first gluestrand and the second glue strand is applied discontinuously.
 5. Amethod according to claim 4, wherein the first glue strand is placeddiscontinuously, with spaces between sections of the first glue strand,and the second glue strand is applied discontinuously, with sections ofthe second glue strand displaced in relation to the sections of thefirst glue strand.
 6. A method according to claim 5, wherein the twoglue strands are applied offset in relation to each other so that thesections of the first glue strand are within spaces between the sectionsof the second glue strand.
 7. A method according to claim 1, wherein thefirst glue strand and the second glue strand are applied to the endjoint surface of the same cylindrical sleeve.
 8. A method according toclaim 7, wherein the first glue strand is applied adjacent the outercylindrical surface of the cylindrical sleeve, and the second gluestrand is applied adjacent the inner cylindrical surface of thecylindrical sleeve.
 9. A method according to claim 8, wherein one of thefirst glue strand and the second glue strand is applied discontinuously.10. A method according to claim 7, wherein the first glue strand and thesecond glue strand are applied discontinuously.
 11. A method accordingto claim 10, wherein the second glue strand is applied in thediscontinuities of the first glue strand.
 12. A method according toclaim 1, wherein the first glue strand is applied to the end jointsurface of a first one of the cylindrical sleeves, and the second gluestrand is applied to the end joint surface of a second one of thecylindrical sleeves.
 13. A method according to claim 12, wherein thefirst glue strand and the second glue strand are applieddiscontinuously.
 14. A method according to claim 1, further comprising:processing the end joint surface of a first one of the cylindricalsleeves to a first desired configuration; and processing the end jointsurface of a second one of the cylindrical sleeves to a second desiredconfiguration, wherein the first desired configuration and the seconddesired configuration permit the end joint surface of the firstcylindrical sleeve and the end joint surface of the second cylindricalsleeve to be joined to provide a secure joining of the first and secondcylindrical sleeves.
 15. An apparatus for end-to-end joining of twocylindrical sleeves, each cylindrical sleeve including an end jointsurface on the end of such cylindrical sleeve, said apparatuscomprising: a first glue nozzle for providing a strand of a first glue;a second glue nozzle for providing a strand of a second glue; a firstalignment device for positioning a first one of the cylindrical sleeves;and a second alignment device for positioning a second one of thecylindrical sleeves, wherein: the alignment devices position one of thecylindrical sleeves adjacent said first glue nozzle, permitting saidfirst glue nozzle to apply the first glue strand on at least a part ofthe width of the end joint surface of that cylindrical sleeve, andposition one of the cylindrical sleeves adjacent said second gluenozzle, permitting said second glue nozzle to apply the second gluestrand on at least a part of the width of the end joint surface of thatcylindrical sleeve, the alignment devices position the cylindricalsleeves with the width of the end joint surface of a first one of thecylindrical sleeves against the width of the end joint surface of asecond one of the cylindrical sleeves, the first glue has propertiesthat cause the first glue strand by itself to fix the end joint surfacesof the cylindrical sleeves within a first time period, the second gluehas properties that cause wetting of the sleeve material in the endjoint surface and its immediate vicinity and setting of the second gluestrand by itself within a second time period, longer than the first timeperiod.
 16. An apparatus according to claim 15, wherein said alignmentdevices position the first one of the cylindrical sleeves adjacent bothsaid first glue nozzle and said second glue nozzle.
 17. An apparatusaccording to claim 15, wherein said alignment devices position the firstone of the cylindrical sleeves adjacent said first glue nozzle andposition the second one of the cylindrical sleeves adjacent said secondglue nozzle.
 18. An apparatus according to claim 15, further comprising:a processing unit for processing the end joint surfaces of thecylindrical sleeves to configurations permitting the end joint surfacesof the cylindrical sleeves to be securely joined.
 19. Apparatusaccording to claim 18, wherein said processing unit comprises aplurality of rails and a milling device for configuring the end jointsurfaces of the cylindrical sleeves.
 20. Apparatus according to claim19, wherein, when one of the cylindrical sleeves in positioned on saidmilling device, said rails extend in the longitudinal direction of suchcylindrical sleeve and are spaced around the circumference of suchcylindrical sleeve.